Published report when datasource reached by hostname, but not IP

Found my problem !
I wasn't able to find the logs or export them as I'm not the PowerBI gateway administrator and it seems like the admin has to login to the software in order to export logs. Here's what I could do however which helped me figure it out. I tracked it down to our firewall which was setup to do some packet inspection to detect applications and had special instruction for specific softwares detected.

The traffic going through the gateway and SQL server was recognized as one application by the firewall, while the traffic to the newer report was recognized as different one that was not on the allowed list.

I found that out by opening a wireshark session on both the gateway and the SQL server. Reviewing packets between the two, I found that the gateway would initiate connexion with the SQL server via a TDS protocol request and could see the request come in on SQLServer. Then, the SQLServer would send a response.
I never saw the response coming in on the gateway , so that set me on a quest to find the missing response packet... that ended-up being dropped by the firewall !

I hope this can help anyone having the same issue!

Have a great day all.